LPIC-1 Practice Test 16 — 15 Questions

Question 1

A system has a software RAID1 array (/dev/md0) with two disks: /dev/sda and /dev/sdb. Disk /dev/sda fails. Which command sequence will replace the failed disk with a new /dev/sdc without stopping the array?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

mdadm --manage /dev/md0 --fail /dev/sda --remove /dev/sda && mdadm --manage /dev/md0 --add /dev/sdc. Mdadm's --manage mode allows hot-replacement of a failed disk in a RAID1 array without stopping it. The --fail flag marks /dev/sda as faulty, --remove detaches it, and --add incorporates the new /dev/sdc, triggering an automatic rebuild of the mirror.

Answer

mdadm --stop /dev/md0; replace disk; mdadm --assemble /dev/md0 /dev/sdb /dev/sdc

Answer

Shutdown system, physically replace disk, reboot

Answer

dd if=/dev/sdb of=/dev/sdc bs=64K

Question 2

After a system upgrade, the server fails to boot with the error: 'ERROR: Failed to mount the real root device.' The root filesystem is on an LVM logical volume. Which recovery step is most appropriate?

Accepted Answer

Boot from a live CD, chroot, and run 'update-initramfs -u -k all' to regenerate the initramfs with lvm2 support. The error 'Failed to mount the real root device' after a system upgrade indicates the initramfs lacks the necessary LVM modules (e.g., lvm2) to activate and mount the root logical volume. Regenerating the initramfs with 'update-initramfs -u -k all' rebuilds it to include LVM support, ensuring the kernel can locate and mount the root filesystem during boot.

Answer

Run 'lvchange -ay' to activate all LVs

Answer

Reinstall GRUB to the MBR

Answer

Use 'fsck' on the root LV

Question 3

A system administrator needs to ensure that the httpd service starts automatically when the system enters the multi-user.target. Which command should be used?

Accepted Answer

systemctl enable httpd. The `systemctl enable httpd` command creates the necessary symlinks in the systemd unit configuration to ensure the httpd service starts automatically when the system enters the multi-user.target. This is the correct method to enable a service to start at boot in a systemd-based Linux system.

Answer

systemctl add-wants multi-user.target httpd.service

Answer

systemctl start httpd

Answer

systemctl set-default multi-user.target

Question 4

You are a junior administrator for a company that uses a standard disk image for all Linux servers. The image is based on CentOS 7. You need to ensure that new servers automatically install all available security updates during the first boot. You plan to run a command in a startup script. Which command should you use?

Accepted Answer

yum update -y. `yum update -y` installs all available updates, including security updates, without prompting for confirmation. On CentOS 7, this command updates all packages to their latest versions, which encompasses security patches. Running this in a startup script ensures that security updates are applied automatically on first boot.

Answer

yum check-update

Answer

yum install yum-cron

Answer

apt-get upgrade -y

Question 5

A company manages a cluster of 50 web servers running Ubuntu 20.04. The servers are configured to synchronize time with an internal NTP server at 10.0.0.100 using the default ntpd. The NTP server itself syncs with external stratum 2 servers. Recently, the security team implemented a restrictive iptables firewall on all servers, allowing only essential services. Several servers in the 10.0.1.0/24 network now report time drift and ntpq -p shows all peers with '?' status. A network engineer runs tcpdump on one affected server and sees no NTP replies from 10.0.0.100. The NTP server's firewall is configured to allow inbound NTP from 10.0.0.0/24 only. The engineer also notes that the server's /etc/ntp.conf contains the line 'restrict 10.0.0.100' (which is incorrect) and that ntpq -crv shows 'sync target not reachable'. Which single action will most directly resolve the synchronization issue for the affected servers?

Accepted Answer

Modify the NTP server's firewall to allow inbound NTP from 10.0.1.0/24.. The affected servers are in the 10.0.1.0/24 network, but the NTP server's firewall only allows inbound NTP from 10.0.0.0/24. Even if the client's firewall permits outbound UDP to port 123, the server will drop the requests because they originate from an unauthorized subnet. Therefore, modifying the NTP server's firewall to accept NTP traffic from 10.0.1.0/24 directly resolves the synchronization issue. Option A (client firewall fix) is necessary but not sufficient because the server will still block the requests. Option B fixes the incorrect restrict line but does not address the firewall. Option D is irrelevant as routing is not the problem.

Answer

Add an iptables rule on the affected server to accept outbound UDP packets to 10.0.0.100 port 123.

Answer

Remove the line 'restrict 10.0.0.100' from /etc/ntp.conf.

Answer

Add a static route on the affected server for 10.0.0.100 via a different gateway.

Question 6

A user reports that they cannot connect to a remote server using SSH. The administrator checks the SSH server status and it is running. Which of the following is the most likely cause?

Accepted Answer

A firewall is blocking port 22.. SSH operates over TCP port 22 by default. If the SSH server is running but the client cannot connect, a firewall blocking port 22 is the most likely cause because it would prevent the TCP handshake from completing, even though the SSH daemon (sshd) is active and listening.

Answer

The client's subnet mask is incorrect.

Answer

The client cannot resolve the server's hostname.

Answer

The SSH server is using UDP instead of TCP.

Question 7

A user downloaded a Debian package file named 'software.deb'. Which command should be used to install it?

Accepted Answer

dpkg -i software.deb. The correct command is `dpkg -i software.deb` because `dpkg` is the low-level package manager for Debian-based systems that directly installs `.deb` files. The `-i` flag tells `dpkg` to install the specified package file from the local filesystem, which is exactly what is needed when you have a downloaded `.deb` file.

Answer

rpm -ivh software.deb

Answer

apt install software.deb

Answer

apt-get install software.deb

Question 8

Which TWO of the following are valid ways to capture the output of a command into a variable in Bash?

Accepted Answer

var=`command`. Option A, var=`command`, is correct because backticks are the legacy command-substitution syntax in Bash: the shell runs command in a subshell and replaces the backtick expression with its standard output, which is then assigned to var. Option C, var=$(command), is correct because the modern $(...) form performs the same command substitution, capturing command's stdout into var, and is preferred since it nests more cleanly and avoids backtick escaping issues. Option B, var={command}, is not valid because braces are used for brace expansion (e.g., {a,b}) and parameter expansion (${var}), not command substitution. Option D, var|command, is not valid because it would attempt to pipe the variable name as a command into another command rather than assign output. Option E, var=command, is not valid because it simply assigns the literal string 'command' to var without executing it or capturing any output.

Answer

var={command}

Answer

var|command

Answer

var=command

Question 9

Refer to the exhibit. A user gets this error when running a script. What is the most likely cause?

Accepted Answer

The script has Windows-style line endings (CRLF).. The error message shown in the exhibit (typically '/bin/bash^M: bad interpreter' or similar) indicates that the script contains carriage return characters (CR, \r) at the end of lines, which is characteristic of Windows-style CRLF line endings. When Linux's Bash tries to interpret the shebang line, it sees '/bin/bash^M' as the interpreter path, which does not exist, causing the script to fail. This is a common issue when scripts are created or edited on Windows and then transferred to a Unix-like system without converting line endings.

Answer

The script is missing a shebang line.

Answer

The script does not have execute permission.

Answer

The script contains a syntax error in line 3.

Question 10

A system administrator notices that after updating the kernel, the system fails to boot. The administrator wants to boot the previous kernel. Which GRUB menu option should be selected?

Accepted Answer

Advanced options for Ubuntu. The 'Advanced options for Ubuntu' GRUB menu entry provides access to a submenu listing all installed kernel versions, allowing the administrator to select and boot the previous kernel. This is the standard method to revert to a known-good kernel after a failed update, as GRUB dynamically generates entries for each kernel found in /boot.

Answer

Memory test

Answer

Recovery mode

Answer

Boot from first hard disk

Question 11

Which command is used to compress a file with the highest compression ratio?

Accepted Answer

xz -9. `xz -9` uses the LZMA2 compression algorithm, which typically achieves a higher compression ratio than gzip (DEFLATE) or bzip2 (Burrows-Wheeler transform) at the cost of slower speed and higher memory usage. The `-9` flag sets the highest compression level, maximizing the ratio.

Answer

gzip -9

Answer

bzip2 -9

Answer

compress

Question 12

A Red Hat system administrator suspects that the files belonging to the 'openssh-server' package have been modified since installation. Which command verifies the integrity of the installed package files?

Accepted Answer

rpm -V openssh-server. The `rpm -V` (verify) command checks the integrity of installed package files by comparing their current attributes (size, MD5 checksum, permissions, etc.) against the original metadata stored in the RPM database. This directly answers the question of whether files belonging to the 'openssh-server' package have been modified since installation.

Answer

rpm -K openssh-server

Answer

rpm -qa | grep openssh

Answer

rpm -q openssh-server

Question 13

Refer to the exhibit. What is the current state of the SSH service?

Accepted Answer

It is active and running. The exhibit shows the output of `systemctl status sshd`, which displays the service state as 'active (running)' in the green text. This indicates that the SSH daemon (sshd) is currently loaded and executing, providing secure shell access to the system. The 'active (running)' state is the normal operational state for a service that has been started and is functioning correctly.

Answer

It is inactive

Answer

It is disabled

Answer

It has failed

Question 14

A system administrator wants to configure log rotation to compress log files daily and keep 30 days of logs. Which of the following configurations achieves this goal?

Accepted Answer

Add a configuration file in /etc/logrotate.d/ with the contents: '/var/log/mylog { daily rotate 30 compress }'. Logrotate is the standard Linux utility for log rotation, compression, and retention. The configuration directive 'daily rotate 30 compress' in a file under /etc/logrotate.d/ instructs logrotate to rotate logs daily, keep 30 rotated copies, and compress old logs with gzip. This directly meets the requirement of daily compression and 30-day retention.

Answer

Set the 'maxlogsize' parameter in /etc/rsyslog.conf

Answer

Create a cron job that runs 'gzip /var/log/mylog.*' daily

Answer

Edit /etc/logrotate.conf to set 'rotate 30 weekly'

Question 15

A small office has a network printer with IP 192.168.1.100. The printer is shared via CUPS. A user reports that they cannot print a document from their workstation. The printer appears in the list of available printers, but when they try to print, the job hangs in the queue with status 'processing'. The administrator suspects the printer may be offline or the CUPS service is not running. Which command should the administrator run first to gather diagnostic information about the printer and its queue?

Accepted Answer

lpstat -t. The `lpstat -t` command shows the complete status of the CUPS print system, including all printers, their queues, and whether they are accepting jobs. Since the job is stuck with 'processing' status, this command will reveal if the printer is idle, disabled, or unreachable, and whether the queue is enabled or paused. It is the first diagnostic step before testing network connectivity or restarting services.

Answer

ping 192.168.1.100

Answer

lpadmin -p printer -E

Answer

systemctl restart cups